Abstract

Through the introduction of gas-phase monomers phthalic anhydride (PA) and p-phenylenediamine (PPD), replenishment of lubricants during high-temperature friction processes could be realized. According to Fourier transform infrared spectroscopy (FTIR) and gas chromatography–mass spectrometry (GC-MS) analyses, in a 10-min ball–disc friction test at 500 °C, the introduced monomers contacted and polymerized in the gas phase to form solid products with the structure of imides or long carbon chains, which provided superior thermal stability. Solid lubricating films were generated on the disc surface by the physical deposition of these polymerized products and then fall off and attach to the contact position of the ball to form a transfer film. Compared to nonlubricated friction, the coefficient of friction (COF) was reduced from 0.54 to 0.24, and the wear rates of the balls and disc were reduced from 8.32 × 10⁻⁶ to 0.65 × 10⁻⁶ mm³·N⁻¹·m⁻¹ and from 2.62 × 10⁻⁴ to 7.48 × 10⁻⁶ mm³·N⁻¹·m⁻¹, respectively. With continued friction but no further introduction of monomers, the solid lubricating film generated in the initial 10 min could provide even more remarkable lubrication for at least the next 15 min, with a minimum COF of 0.01. This could be related to the reinforcing and synergistic lubricating effect of carbonized product powders that gradually formed a continuous phase on the polymerized products’ matrix. After the COF increased, low friction could be re-attained by reintroduction monomers, but lubrication would be limited by the previous wear. This novel lubricating film shows potential in high-temperature lubrication, because it has both the effectiveness and stability of solid lubrication and the replenishability of gas lubrication.

摘要

通过引入气相单体邻苯二甲酸酐（PA）和对苯二胺（PPD），可以实现高温摩擦过程中润滑剂的补充。根据傅里叶变换红外光谱 (FTIR) 和气相色谱-质谱 (GC-MS) 分析，在 500 °C 的 10 分钟球盘摩擦试验中，引入的单体在气相中接触并聚合形成固体具有酰亚胺或长碳链结构的产品，具有优异的热稳定性。这些聚合产物通过物理沉积在圆盘表面产生固体润滑膜，然后脱落并附着在滚珠的接触位置形成转移膜。与无润滑摩擦相比，摩擦系数 (COF) 从 0.54 降低到 0.24，⁻⁶至 0.65 × 10 ^-6 mm ³ ·N ^-1 ·m ^-1和从 2.62 × 10 ^-4至 7.48 × 10 ^-6 mm ³ ·N ^-1 ·m ^-1， 分别。在继续摩擦但没有进一步引入单体的情况下，最初 10 分钟内产生的固体润滑膜可以在至少接下来的 15 分钟内提供更显着的润滑，最小 COF 为 0.01。这可能与逐渐在聚合产品基体上形成连续相的碳化产品粉末的增强和协同润滑作用有关。COF 增加后，重新引入单体可以重新获得低摩擦，但润滑将受到先前磨损的限制。这种新型润滑膜在高温润滑方面显示出潜力，因为它既具有固体润滑的有效性和稳定性，又具有气体润滑的可补充性。